Can HEPA Filters Be Used to Make DIY Face Masks?




《Can HEPA Filters Be Used to Make DIY Face Masks?》有44条评论

  1. I know is hard to believe, but this is real. I am from Thailand, Last year I accidentally came to know that I have contracted Hepatitis B. I actually don’t know how or when I contracted it but I have it, I was so depressed to know about it, but worldherbsclinic HBV HERBAL FORMULA was a blessing for me, I am thankful to everyone here. After three months of using their HBV HERBAL FORMULA, my test result came out negative.

  2. If I used the pleated material from a 3M Filtrete 2800 furnace filter, and cut it with scissors into a piece that would slide in between the layers of the best homemade mask materials you recommend, would that increase the ability of the mask to capture virus particles? The idea is that once you get that furnace filter apart, there is a lot of pleated material and it is very flexible and easy to breathe through. Then you could simply discard the filter material and wash the mask at the end of the day.

  3. I’d like to follow up on the question about HEPA vacuum bag filters. How can we tell if there are glass fibers or meltblown? I’ve heard they are unsafe due to the potential to have glass particles inhaled. I’ve also heard that HEPA vacuum bags don’t have any fiberglass. Then the articles says that even if it does, it’d likely be “nuisance”. So, clearly results show it filters well. The question is very simply are HEPA vacuum bags safe as mask inserts or not? Thanks,

    • Hi Dan. Song here. Yes, you are so right about those dangerous glass fibers. HEPA is definitely a good option for masks inserts, on condition that make sure the HEPA is made of PP/PET not glass fiber.

  4. It is not true that HEPA filter is breathable (easily). I sealed the filter around my face to see if I could actually breathe in and out, and HARDLY any air was coming in or out, because it is so tightly messed. So the air I breathe in and out once I put the filter in a re-usable mask, is really coming from around the perimeter of the filter and mask. That’s what I realized. Please try breathe through the filter, and you will know what I’m talking about.

  5. Hi Liz,

    • Hi BK, Liz here 🙂 The test we’ve done here is based on one single layer of HEPA filter, you can expect a 95% filtration rate of the tiny particles down to 0.3 microns or below. Just make sure that your DIY mask is well sealed on the edge and fit well with your face! We used HEPA filter in an air purifier, but do you mean HEPA filter bag for vacuum cleaner? If so, feel free to shoot us an email with the picture of the layers, so our engineer can take a look at that for you.

  6. If you use the vacuum cleaner bag hepa filter, is there one direction that is easier to breath and should be towards the face or are either side equally good?

    • Hi K.H. Liz here. If you use a HEPA filter, make sure the HEPA is made of PP/PET not glass fiber for it may shed tiny fiber particles that may be inhaled into your lungs. For the direction, the fluffy side should be facing out and the smooth side facing your mouth. the fluffy texture is used to capture the particles.

  7. Hello! Is there any place to purchase filters that you could insert into your homemade face mask (to not risk damaging the material)? Also, how should you wash and clean these filters (or do you not)?

  8. Hello, in your article you discuss that an insignificant number of small fibers may break off of the filters. What are your thoughts if you purchase a HEPA filter (which has been cut into a small piece) to insert into the filter pocket of a cotton mask? Logically, this would appear to reduce the risk of ingesting these small fibers, however, would this be adequate?

    • Hi Grace, Liz here! That’s a good question! I looked it up, the fibers that broke off the filters were on average 1.5 microns in diameter and 24 microns in length. A cotton cloth from a cotton T-shirt can block 47% 0.3 microns particles. So I’d say yes it will help! maybe not to filter out all shedding fibers, but a significant amount of them.

    • Good question Mariette! The material in HEPA filters is very similar to that in masks. HEPA filters have an extra layer of PET which gives them rigidity, which is different from masks.

      • N95 masks are also different in that the fibers are electrostatically charged. The material in HEPA filters are not necessarily charged, although some may be.

        • Isn’t the electrostatic charge a critical part of filtration?? I read it is needed to get the small particles to stick to the mask.

    • Hi Norman, Liz here. We haven’t tested any combined material yet. A PM2.5 insert is usually something similar to a HEPA filter. So I would guess the mask you described should work at least better than a single HEPA layer. We know there’s a huge demand for reliable, science-backed data right now, so we’ve created a campaign to gather information on what our readers want to test. To vote on what test you expect to see and support our campaign, visit our page here:

  9. Where can I purchase hepa filters? Which manufacturers sell them? Thanks for the useful article.

  10. I’ve been to the ER twice and hospitalized for 4 days, and am having recurrent respiratory stress and distress since wear my first HEPA mask about 2 months ago. I have to do several breathing treatments at home each day, and still Cannabis cough out whatever is in my bronchioles. Just in case, I would suggest against them.

    • Hi Donna, I’m so sorry to hear that the HEPA mask caused the issues! Hope you are getting better now. May I know more details of what’s going on? What type of HEPA did you use? What’s the manufacture? Did you have a previous pulmonary respiratory condition? Do you have any hospital documentation with evidence that the issues are caused by the HEPA mask? If so please kindly share these with us! We will change our article content accordingly or adding in more details! Thank you, and stay safe!

  11. Have you heard of Filti? Face mask material using nanofiber technology. Claims to be up to 95% efficient on submicron particles. Would be interested in the results and your opinion of this material.

    • Hi, Mengi, we haven’t tested Filti yet. We know there’s a huge demand for reliable, science-backed data right now, so we’ve created a campaign to gather information on what our readers want to test. To vote on what test you expect to see and support our campaign, visit our page here:

  12. Very helpfull, learned alot reading your blog.
    Personally fibers breaking off so close to my face is something I rather not risk.

    Seeing as you guys test alot of materials, do you maybe have like an indication how european en14683 type 2 masks perform.
    Their BFE percentage is >98% but unlike US ASTM, testing the PFE value is not necessary and its really hard to find out.
    (Currently trying to get it from a few european manufacturers but it seems they are rather more interrested in who I work for than answering y simple question)

  13. I found this at Walmart to make liners to go into a cloth mask wouldn’t this be as efficient as a N95 mask
    Fabric Meltblown Nonwoven Fabric Original Cloth Material Filter Fabric
    1: Fine Craft: The diameter of melt-blown fiber can reach 1 ~ 2 microns, which belongs to ultra-fine non-woven fiber.
    2: Practical in Use: The cloth features the weight of 25g(about), which will meet your needs.
    3: Proper Sizes: The cloth features the width of 17.5cm/6.89in(about), and it features multiple lengths for optional, which includes(about) 5m/196.80in, 15m/590.5in, 25m/984.2in, 4: Wide Application: The filter fabric meltblown cloth is universal , thus making the filtering efficiency greater than 95%.
    5: Premium Material: The fabric meltblown cloth features a new generation of environmentally friendly materials, which is breathable, flexible, lightweight, non-burning, easy to decompose, non-toxic, non-irritating, recyclable, etc.
    Name: Meltblown Cloth
    Main ingredients: polypropylene
    Width: 17.5cm/6.89in
    5m/196.80in, 15m/590.5in, 25m/984.2in, Functions: heat insulation, heat preservation, insulation, non-toxic and non-irritating.
    Uses: can be used as the filter materials, oil-absorbing materials, sanitary materials such as rags, filtering layers, etc.
    Packing List(about):
    1 x Meltblown Cloth ( 25m/984.2in, )
    Filter Fabric Meltblown Nonwoven Fabric Original Cloth Material Filter

  14. Thank you for your blog. I read your artices with great interest. I May i bring your attention to evolon CR as material for DIY masks. Like the hepa filter it should block small partikels. It is very breathable (a lot more then op masks), With it’s micro-filamented structure it dont shed respirable particles and at it is used as packing material it is cheap (relative). It can be washed with temperatures up to 95 degrees. For me this sound very good and easier as unfold a filter

    • Hi Ulli, Liz here. We haven’t tested evolon yet. We know there’s a huge demand for reliable, science-backed data right now, so we’ve created a campaign to gather information on what our readers want to test. To vote on what test you expect to see and support our campaign, visit our page here:

  15. This was very helpful, thank you.
    Have you tried vacuum cleaner bags?
    There are a variety of bags, including those that are supposed to keep allergens in the bag.

    Thanks, again,


    • This is a very good question! I am curious as well. I am a mother to 3 very young kids and want to make them the best effective masks as possible.
      From Illinois



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